Abstract: In order to investigate the influence of different joint angles on the tunnel stability in deep mining process，a tunnel model with different joint angles was established，and the analysis of tunnel stability based on the ubiquitous-joint constitutive model was carried out.The stability analysis index，which served as a basis for evaluating the influence of tunnel stability，was defined in terms of stress，displacement and plastic zone.It was found that with the change of joint angle，the roof sag and the floor heave of the tunnel were both decreased，while the change of wall convergence was small.The stress concentration increased with the increasing joint angle，and the concentrated area was focused on the tunnel，besides the size of the concentrated area was decreased.The plastic zone distribution around the tunnel was orthogonal to the joint and the range was obviously influenced by joint angle.Firstly，the plastic zone distribution was gathered in the roof，and then transferred to two sides with the increasing joint angle，and the range was obviously influenced by joint angle.Therefore，in the process of deep tunnel support，the influence of anisotropy should be taken into consideration.

Key words: Tunnel stability, FLAC3D, Ubiquitous-joint model, Anisotropy